XP Home has an administrator account also. It is usually kind of hidden but it is there. As far as Pro over Home I don't think there is any big difference for most users. Pro does allow for a 2 CPU system while Home does not. There are also some more bells and whistles in Pro and some fancier networking things. I have found for most of my customers Home is fine. Only for the real power users or pros do I offer Pro. If the $50 difference doesn't bother you then go for Pro.
My PC experience has been limited to WinME for the past 3 years and I've been largely able to do what I've needed to do, using it. However, more and more I'm running into areas where XP would clearly be a better choice. Okay, if I upgrade, is there any reason to choose XP Home over Pro? Everything I've seen seems to say there's no downside to Pro (ignoring $), but for my needs, there may be: I have a small ad hoc WiFi network (with WEP and no neighbors) between 3 PCs, I'm the only user and I've set up WinME so there's no log-ins, ever. Can XP Pro be set up this way also, or would the "administrator-less" nature of XP Home be a better choice?